<?php
namespace Leaps\Database\Schema\Grammars;
use Leaps\Support\Fluent;
use Leaps\Database\Schema\Blueprint;
class PostgresGrammar extends Grammar
{

    /**
     * The keyword identifier wrapper format.
     *
     * @var string
     */
    protected $wrapper = '"%s"';

    /**
     * The possible column modifiers.
     *
     * @var array
     */
    protected $modifiers = array (
            'Increment',
            'Nullable',
            'Default'
    );

    /**
     * The columns available as serials.
     *
     * @var array
     */
    protected $serials = array (
            'bigInteger',
            'integer'
    );

    /**
     * Compile the query to determine if a table exists.
     *
     * @return string
     */
    public function compileTableExists()
    {
        return 'select * from information_schema.tables where table_name = ?';
    }

    /**
     * Compile a create table command.
     *
     * @param \Leaps\Database\Schema\Blueprint $blueprint
     * @param \Leaps\Support\Fluent $command
     * @return string
     */
    public function compileCreate(Blueprint $blueprint, Fluent $command)
    {
        $columns = implode ( ', ', $this->getColumns ( $blueprint ) );
        return 'create table ' . $this->wrapTable ( $blueprint ) . " ($columns)";
    }

    /**
     * Compile a create table command.
     *
     * @param \Leaps\Database\Schema\Blueprint $blueprint
     * @param \Leaps\Support\Fluent $command
     * @return string
     */
    public function compileAdd(Blueprint $blueprint, Fluent $command)
    {
        $table = $this->wrapTable ( $blueprint );
        $columns = $this->prefixArray ( 'add column', $this->getColumns ( $blueprint ) );
        return 'alter table ' . $table . ' ' . implode ( ', ', $columns );
    }

    /**
     * Compile a primary key command.
     *
     * @param \Leaps\Database\Schema\Blueprint $blueprint
     * @param \Leaps\Support\Fluent $command
     * @return string
     */
    public function compilePrimary(Blueprint $blueprint, Fluent $command)
    {
        $columns = $this->columnize ( $command->columns );
        return 'alter table ' . $this->wrapTable ( $blueprint ) . " add primary key ({$columns})";
    }

    /**
     * Compile a unique key command.
     *
     * @param \Leaps\Database\Schema\Blueprint $blueprint
     * @param \Leaps\Support\Fluent $command
     * @return string
     */
    public function compileUnique(Blueprint $blueprint, Fluent $command)
    {
        $table = $this->wrapTable ( $blueprint );
        $columns = $this->columnize ( $command->columns );
        return "alter table $table add constraint {$command->index} unique ($columns)";
    }

    /**
     * Compile a plain index key command.
     *
     * @param \Leaps\Database\Schema\Blueprint $blueprint
     * @param \Leaps\Support\Fluent $command
     * @return string
     */
    public function compileIndex(Blueprint $blueprint, Fluent $command)
    {
        $columns = $this->columnize ( $command->columns );
        return "create index {$command->index} on " . $this->wrapTable ( $blueprint ) . " ({$columns})";
    }

    /**
     * Compile a drop table command.
     *
     * @param \Leaps\Database\Schema\Blueprint $blueprint
     * @param \Leaps\Support\Fluent $command
     * @return string
     */
    public function compileDrop(Blueprint $blueprint, Fluent $command)
    {
        return 'drop table ' . $this->wrapTable ( $blueprint );
    }

    /**
     * Compile a drop table (if exists) command.
     *
     * @param \Leaps\Database\Schema\Blueprint $blueprint
     * @param \Leaps\Support\Fluent $command
     * @return string
     */
    public function compileDropIfExists(Blueprint $blueprint, Fluent $command)
    {
        return 'drop table if exists ' . $this->wrapTable ( $blueprint );
    }

    /**
     * Compile a drop column command.
     *
     * @param \Leaps\Database\Schema\Blueprint $blueprint
     * @param \Leaps\Support\Fluent $command
     * @return string
     */
    public function compileDropColumn(Blueprint $blueprint, Fluent $command)
    {
        $columns = $this->prefixArray ( 'drop column', $this->wrapArray ( $command->columns ) );
        $table = $this->wrapTable ( $blueprint );
        return 'alter table ' . $table . ' ' . implode ( ', ', $columns );
    }

    /**
     * Compile a drop primary key command.
     *
     * @param \Leaps\Database\Schema\Blueprint $blueprint
     * @param \Leaps\Support\Fluent $command
     * @return string
     */
    public function compileDropPrimary(Blueprint $blueprint, Fluent $command)
    {
        $table = $blueprint->getTable ();
        return 'alter table ' . $this->wrapTable ( $blueprint ) . " drop constraint {$table}_pkey";
    }

    /**
     * Compile a drop unique key command.
     *
     * @param \Leaps\Database\Schema\Blueprint $blueprint
     * @param \Leaps\Support\Fluent $command
     * @return string
     */
    public function compileDropUnique(Blueprint $blueprint, Fluent $command)
    {
        $table = $this->wrapTable ( $blueprint );
        return "alter table {$table} drop constraint {$command->index}";
    }

    /**
     * Compile a drop index command.
     *
     * @param \Leaps\Database\Schema\Blueprint $blueprint
     * @param \Leaps\Support\Fluent $command
     * @return string
     */
    public function compileDropIndex(Blueprint $blueprint, Fluent $command)
    {
        return "drop index {$command->index}";
    }

    /**
     * Compile a drop foreign key command.
     *
     * @param \Leaps\Database\Schema\Blueprint $blueprint
     * @param \Leaps\Support\Fluent $command
     * @return string
     */
    public function compileDropForeign(Blueprint $blueprint, Fluent $command)
    {
        $table = $this->wrapTable ( $blueprint );
        return "alter table {$table} drop constraint {$command->index}";
    }

    /**
     * Compile a rename table command.
     *
     * @param \Leaps\Database\Schema\Blueprint $blueprint
     * @param \Leaps\Support\Fluent $command
     * @return string
     */
    public function compileRename(Blueprint $blueprint, Fluent $command)
    {
        $from = $this->wrapTable ( $blueprint );
        return "alter table {$from} rename to " . $this->wrapTable ( $command->to );
    }

    /**
     * Create the column definition for a string type.
     *
     * @param \Leaps\Support\Fluent $column
     * @return string
     */
    protected function typeString(Fluent $column)
    {
        return "varchar({$column->length})";
    }

    /**
     * Create the column definition for a text type.
     *
     * @param \Leaps\Support\Fluent $column
     * @return string
     */
    protected function typeText(Fluent $column)
    {
        return 'text';
    }

    /**
     * Create the column definition for a integer type.
     *
     * @param \Leaps\Support\Fluent $column
     * @return string
     */
    protected function typeInteger(Fluent $column)
    {
        return $column->autoIncrement ? 'serial' : 'integer';
    }

    /**
     * Create the column definition for a big integer type.
     *
     * @param \Leaps\Support\Fluent $column
     * @return string
     */
    protected function typeBigInteger(Fluent $column)
    {
        return $column->autoIncrement ? 'bigserial' : 'bigint';
    }

    /**
     * Create the column definition for a medium integer type.
     *
     * @param \Leaps\Support\Fluent $column
     * @return string
     */
    protected function typeMediumInteger(Fluent $column)
    {
        return 'integer';
    }

    /**
     * Create the column definition for a tiny integer type.
     *
     * @param \Leaps\Support\Fluent $column
     * @return string
     */
    protected function typeTinyInteger(Fluent $column)
    {
        return 'smallint';
    }

    /**
     * Create the column definition for a small integer type.
     *
     * @param \Leaps\Support\Fluent $column
     * @return string
     */
    protected function typeSmallInteger(Fluent $column)
    {
        return 'smallint';
    }

    /**
     * Create the column definition for a float type.
     *
     * @param \Leaps\Support\Fluent $column
     * @return string
     */
    protected function typeFloat(Fluent $column)
    {
        return 'real';
    }

    /**
     * Create the column definition for a decimal type.
     *
     * @param \Leaps\Support\Fluent $column
     * @return string
     */
    protected function typeDecimal(Fluent $column)
    {
        return "decimal({$column->total}, {$column->places})";
    }

    /**
     * Create the column definition for a boolean type.
     *
     * @param \Leaps\Support\Fluent $column
     * @return string
     */
    protected function typeBoolean(Fluent $column)
    {
        return 'boolean';
    }

    /**
     * Create the column definition for an enum type.
     *
     * @param \Leaps\Support\Fluent $column
     * @return string
     */
    protected function typeEnum(Fluent $column)
    {
        return 'varchar(255)';
    }

    /**
     * Create the column definition for a date type.
     *
     * @param \Leaps\Support\Fluent $column
     * @return string
     */
    protected function typeDate(Fluent $column)
    {
        return 'date';
    }

    /**
     * Create the column definition for a date-time type.
     *
     * @param \Leaps\Support\Fluent $column
     * @return string
     */
    protected function typeDateTime(Fluent $column)
    {
        return 'timestamp';
    }

    /**
     * Create the column definition for a time type.
     *
     * @param \Leaps\Support\Fluent $column
     * @return string
     */
    protected function typeTime(Fluent $column)
    {
        return 'time';
    }

    /**
     * Create the column definition for a timestamp type.
     *
     * @param \Leaps\Support\Fluent $column
     * @return string
     */
    protected function typeTimestamp(Fluent $column)
    {
        return 'timestamp';
    }

    /**
     * Create the column definition for a binary type.
     *
     * @param \Leaps\Support\Fluent $column
     * @return string
     */
    protected function typeBinary(Fluent $column)
    {
        return 'bytea';
    }

    /**
     * Get the SQL for a nullable column modifier.
     *
     * @param \Leaps\Database\Schema\Blueprint $blueprint
     * @param \Leaps\Support\Fluent $column
     * @return string null
     */
    protected function modifyNullable(Blueprint $blueprint, Fluent $column)
    {
        return $column->nullable ? ' null' : ' not null';
    }

    /**
     * Get the SQL for a default column modifier.
     *
     * @param \Leaps\Database\Schema\Blueprint $blueprint
     * @param \Leaps\Support\Fluent $column
     * @return string null
     */
    protected function modifyDefault(Blueprint $blueprint, Fluent $column)
    {
        if ( ! is_null ( $column->default ) ) {
            return " default " . $this->getDefaultValue ( $column->default );
        }
    }

    /**
     * Get the SQL for an auto-increment column modifier.
     *
     * @param \Leaps\Database\Schema\Blueprint $blueprint
     * @param \Leaps\Support\Fluent $column
     * @return string null
     */
    protected function modifyIncrement(Blueprint $blueprint, Fluent $column)
    {
        if ( in_array ( $column->type, $this->serials ) and $column->autoIncrement ) {
            return ' primary key';
        }
    }
}